Light duty liquid detergent



United States Patent 3,029,205 LIGHT DUTY LIQUID DETERGENT Lloyd F.Henderson, Fair Lawn, and Francis E. Carroll,

Glen Rock, N.J., assignors to Lever Brothers Company, New York, N.Y., acorporation of Maine No Drawing. Filed May 5, 1958, Ser. No. 732,817 7Claims. (Cl. 252-161) This invention relates to a concentrated liquiddetergent solution for dishwashing and light detergent use which remainsclear and uniform without separation of solid materials at temperaturesas low as 45 F., has good detergency and is high in sudsing power.

Liquid detergents which are solutions of synthetic detergents areavailable which are useful in washing dishes and slightly soiledfabrics. Such detergents possess special properties attractive to thehousewife. There is no need to dissolve the detergent. A washingsolution is obtain able simply upon dilution of an easily measuredportion of the concentrated liquid with water. However, a liquiddetergent should be a clear light-colored liquid, preferably of lowviscosity and should not become cloudy or precipitate solids even at lowtemperatures which may be encountered in storage, to avoid adeterioration in performance due to separation of active ingredients.This circumstance, coupled with the necessity of providing highlyconcentrated solutions, had made it difiicult to formulate a liquiddetergent which would meet the needs of light detergent use and still becompetitive from a price standpoint with the dry powderedpolyphosphatebuilt anionic detergent product. The dry product of courseneed not meet special solubility requirements.

It is imperative that the liquid detergent solution be highlyconcentrated in order to keep at a minimum the volume of solvent in theconcentrate and the measured portions used for each wash. Theconcentration of a liquid detergent for dishwashing should be increasedto a point at which four grams of the product when used at 116 F. in sixquarts of water of 300 p.p.m. or softer will wash a minimum of thirtyplates before suds cease to cover completely the surface of the washwater. This specification is based on plates each soiled with 4.5 gramsof a standard soil made up of nine parts of a vegetable shortening andeight parts of flour. This is a rigorous specification. A solution of a43.5% concentration of sodium phenyl polypropylene sulfonate (theremainder being solvents) will wash less than 30 plates under theseconditions.

Light duty liquid detergents are also recommended for fine fabricwashing. To be satisfactory for this purpose, four grams of the productin six quarts of water of 300 ppm. or softer at 110 to 125 F. using anartificially soiled fabric should have a rating of at least 27 to 28D.U.s as measured in the Hunter reflectometer.

Many nonionic detergents are sufficiently soluble in ice Sodium salts ofphenyl polypropylene sulfonic acids, for example, are soluble in wateronly to the extent of 2% at 77 F., increasing to 24% detergent at 77 F.,if a solubilizing sulfonate or lower molecular weight, such as hexylbenzene sulfonate, is employed. These solutions are saturated, however,and must be diluted to prevent precipitation of solids if they are to beused or stored at lower temperatures. Also, low molecular weightsulfonate solubilizers appear to affect sudsing adversely.

If a low molecular weight alcohol is used as a solvent, solutionscontaining as much as 20% sodium phenyl polypropylene sulfonatedetergent are obtainable. However, these maximum concentrations are wellbelow that required for a satisfactory liquid detergent. Even a solutioncontaining 43.5% active phenyl polypropylene sulfonate isunsatisfactory, taking into account the specifications mentioned above.

It is evident that no one yet has shown how to incorporate a phenylpolypropylene sulfonate in a liquid detergent which yvill remain clear,homogeneous and pourable at low room temperatures, at least down to 45F., when highly concentrated, and with balanced sudsing and detergentproperties.

In accordance with the instant invention, a light duty liquid detergentsolution is provided which contains a phenyl polypropylene sulfonate andwhich meets the above rewater to permit marketing in liquid solutionform in high concentrations. One commercial liquid preparation utilizesan alkyl aryl polyethylene glycol as the detergent and contains 81%active detergent. However, this class of nonionic detergents like mostif not all nonionic detergents, is deficient in sudsing and many fewerplates can be washed before disappearance of suds in a dishwashingoperation than when anionic detergents are used.

Another commercial liquid detergent utilizes the ammonium salts of fattyalcohol sulfates. These are more soluble than the corresponding sodiumand potassium salts, but require bolstering with a monoalkanolamide suchas lauric ethanolamide to improve sudsing.

Both of these types of liquid detergents are quite expensive, comparedto the readily available alkyl'aryl sulfonates. Alkyl aryl sulfonateshave not however been used in liquid detergents in high concentrations.

quirements. This is made possible by a combination of the substantiallysalt-free phenyl polypropylene sulfonate detergent with a detergentpolyethylene oxide thioor oxyether of a hydrophobic hydroxy compound,the total detergent concentration amounting to at least 50% by weight ofthe solution. Water and a water-miscible aliphatic alcohol of lowmolecular weight, the latter not exceeding 40% by weight of thesolution, are the solvents.

The phenyl polypropylene sulfonate should be substantially salt-free(i.e., not over 0.2% salt as Na SO This is of some importance in aliquid detergent, because the apparent solubility in water of the phenylpolypropylene sulfonate thereby is much improved. However, thesolubility is not sufficiently improved solely by the absence of salt tomake a phenyl polypropylene sulfonate liquid detergent practical, evenwith use of an alcohol solvent, as shown by the following data forsalt-free sodium phenyl polypropylene sulfonate:

TABLE I Composition (percent) Phenyl poly- Isopro- Condition ofCondition of propyl- NazSO H20 pyl al- Composition Composition ens001101 at 72 F. at 45 F. sulfonote 10 15 67. 5 7. 5 Separates intoPreeipitate.

two layers.

8 12 72 8 Clear liquid Do.

6 9 69. 7 15.3 do Separates into three layers, precipitate.

6 9 68 17 Separates into Separates into 1 two layers. three layers. 1684 Clear liquid Solid. 20 72 8 do Separates into two layers. 40 48 12Separates into Do.

two layers. 50 25 25 Clear 1iquid Do.

In no case above is it possible to reach the lower limit of 50% activedetergent concentration for a practical liquid detergent solution, evenat the very high 25% level of alcohol. 7

This objective of the instant invention is however acand a tertiaryalkyl carbon at the benzene ring, and have the following generalstructure:

where M is hydrogen, an alkali metal or an organic amine TABLE IIComposition, percent Condition of composition at- No. Na NPG Alcohol-Oronite 1 101 2 H H 72 F 45 F. 22 F.

ratio 1:1

1. 16 84 Clear liquid Solid 2 32 8 60 Cloudy very viscous liquid.Separates Opaque solid into two layers on standing; both very viscous.3- 20 Clear viscous liquid Cloudy viscous liquid. Separates into twolayers; supernatant clear, bottom cloudy. 4 8 do Clear very viscousliquid 5. 16 do Very viscous, slightly cloudy liquid 6 Clear Separates.7 40 Clear.

1 Phenyl polypropylene sulfonate sodium salt (salt-free).

2 Nonyl phenol condensed with from eight to ten moles of'ethylene oxide.

Composition 2 shows that 1 part alkyl phenol ether detergent to 4 partsphenyl polypropylene sulfonate is too low to show a solubilizing effect.In composition 3, the effect begins to be noticeable, and in composition4 it is very evident. Composition 5 has 55% active detergent, but iscloudy and viscous at F. None of these compositions would be regarded assuitable. Compositions 6 and 7 illustrate the solubilizing effect of thealkyl phenol ether detergent when an alcohol is used as a solvent.

All of these compositions have a lower proportion of detergent (40% orless) than is desirable, from the standpoint of the specificationsmentioned above.

In accordance with the invention, the clarity and viscosity of theliquid detergents are kept up to the requirements at temperatures as lowas 45 F. in all cases, and even lower in many instances, by addition ofa watermiscible alcohol of low molecular weight in an amount up to about40% by weight of the liquid detergent. The balanced sudsing anddetergency are obtained when from one to twenty parts of the phenylpolypropylene sulfonate are used to each three to one parts of alkyl oraralkyl ether detergent.

Expressed in percents, when the phenyl polypropylene and alkyl oraralkyl ether are the only detergents, the proportion will range from 25to 95% phenyl polypropylene sulfonate, 40 to 85% being preferred, andfrom 75 to 5% alkyl or aralkyl ether, 60 to 15% being preferred, basedon the total active detergent concentration.

Liquid detergents of the invention containing a phenyl polypropylenesulfonate and alkyl or aralkyl ether detergent in the proportionsindicated have a higher sudsing and detergency than either of thesedetergents alone, in the same amounts, as demonstrated by standardizedtests.

The total amount of detergents can be widely varied and from to 80% byweight of the solution would be employed ordinarily. The amount of thedetergent is determined by the specifications for light duty liquiddetergents set forth heretofore. From 40 to 65% total detergent byweightof the solution is preferred.

The sulfonated phenyl polypropylene alkanes are characterized by thebranched chain structure of polypropylene V cation, and R and R arealkyl, of the type formula C H where the whole alkyl chain containspreferably twelve to fifteen carbon atoms and at least one R is apolypropylene group. These are known compounds, whose preparation andproperties are set forth in US. Patent No. 2,477,383 to Lewis, issuedJuly 26, 1949; they are available in commerce under the trade namesOronite, Neolene 400 (Sharples Chemical Co.) and Ultrawet.

The anionic phenyl polypropylene sulfonate detergents can be used in theform of the free acid, which can be neutralized in situ in the liquiddetergent solution by addition of an organic amine or ammoniumhydroxide. They are also readily available as the alkali metal salts,such as sodium, potassium and ammonium, and these would generally beused. However, the ammonium or organic amine salts may be more soluble,and in this event would be preferred, particularly from the standpointof increasing the detergent concentration to a maximum.

The detergent polyethylene oxide thioand oxyethers of a hydrophobicorganic hydroxy compound have the general formula:

where R is a straight or branched chain saturated or unsaturatedhydrocarbon group having from eight to eighteen carbon atoms, such as analkyl group or an aralkyl group having an alkyl group of from eight totwelve carbon atoms and attached to A through the aryl nucleus, A isoxygen or sulfur, and x is a number from eight to twenty.

When R is alkyl it will be evident that the detergent can e regarded asderived from an alcohol or mercaptan of high molecular weight, bycondensation with ethylene oxide. Typical of this type of alkyl etherare the condensation products of dodecyl alcohol or mercaptan with fromeight to seventeen moles of ethylene oxide. Nonionic 218,? thecondensation product of dode'cyl mercaptan with from eight to seventeenmoles of ethylene oxide,

R A-[CHrGHnOIr-CHrOHaOH where R is a straight or branched chainhydrocarbon group having at least eight carbon atoms up to approximatelyeighteen carbon atoms, A is oxygen or sulfur and x is a number fromeight to twenty. Typical are the condensation products of octyl andnonyl phenol and thiophenol with from eight to seventeen moles ofethylene oxide.

Typical alkyl groups in the above compounds are, for example, straightor branched octyl, nonyl, decyl, lauryl, oleyl, cetyl, myristyl orstearyl groups.

Commercial products are Triton X-l00, the condensation product of octylphenol with eight to twelve moles of ethylene oxide (Rohm & Haas),NPG-lOl (Carbon and Carbide Chemical Company), Igepal CO and Antarox A400, both condensation products of alkyl phenol (alkyl of from eight tosixteen carbon atoms) with eight to twenty moles of ethylene oxide,(General Aniline), Neutronyx 600 (Onyx Oil and Chemical Co.), and NI8586 and NI 8190 (Oronite Chemical Co.), Nonionic 218 (Sharples ChemicalCo.) and Sterox SE (Monsanto Chemical Co.).

These detergents, in conjunction with the phenyl polypropylenesulfonate, are capable of producing a light dutyliquid detergent whosedetergency is very satisfactory for dishwashing and like light washinguses.

The lower limit of x is important from the standpoint of detergency.Lower monoalkyl ethers of polyethylene glycol such as ethylene glycolmonoether of iso-octyl phenol are not useful, and do not show anenhanced sudsing. The data reproduced below makes this evident.

The superiority of the higher polyethylene glycol ether in number ofdishes washed is very marked.

Since the amount of water which the liquid detergent solution willtolerate without clouding or the formation of precipitates is critical,a Water-miscible aliphatic alcohol of low molecular weight can be addedto improve stability against clouding and precipitation, and/ or reduceviscosity. Up to approximately 40% alcohol by weight of the solution canbe used, the upper limit being controlled by the eifect of the alcoholon the viscosity of the solution.

Usually from 5 to 20% alcohol by weight of the solution is sufficient tomeet the solutions particular requirements. Ethyl alcohol is preferred,but the chain length of the alcohol is not critical; methyl, propyl andisopropyl alcohols can be used.

Thus the solvent mixture employed in formulating the liquid detergentsof the invention will comprise water and an alcohol and the relativeproportions of these two solvents are not critical but will be takenwith due consideration to the detergent and other components to producea detergent solution which does not cloud or form a precipitate attemperatures as low as 45 F. In general, it will be desirable to limitthe amount of water to no more than equal that of the alcohol used.

The composition may also contain dyestuffs and perfumes to suit thehousewifes desire. It is customary to mask the petroleum odor of phenylpolypropylene sulfonates, and characteristic sulfur odor of thioethernonionic detergents, and those skilled in the art are aware of perfumeswhich meet this need.

Formulations containing about 41% phenyl polypropylene sulfonates, about27% ethoxynated alkyl phenol (active basis), 15.5% ethyl alcohol and theremainder water exemplify an application of the principles of selectionenumerated above, and display a detergency which is very adequate fordishwashing and light washing use, comparing favorably to dry powderedpolyphosphate-built alkyl aryl sulfonate detergents in this respect. Theabove applies to use of the sodium and potassium salts of the phenylpolypropylene sulfonate. Solubility is at a maximum when ammonium ororganic amine salts of the anionic detergent are used.

The above is a preferred embodiment of the liquid detergent of theinvention. When prepared using ammonium or amine salts of thedetergents, it remains clear at temperatures as low as 0 F. Otherexemplifying embodiments follow.

In the examples the dishwashing test data was obtained according to thefollowing standardized test: Six quarts of water of the desired hardnesswas adjusted to a temperature of 116 F. and the detergent composition tobe tested dissolved therein in a concentration of 30 grams. Both softand hard waters 50 ppm. and p.p.rn. generally are used. The solutionsare adjusted to ensure complete solution and then allowed to stand for45 seconcls at which time dishwashing is begun using plates soiled witha standardized soil composition. Plates are washed until the suds nolonger completely cover the surface of the water.

Example 1 A Well balanced formulation of which sixteen ounces isequivalent for light duty use to nineteen or twenty ounces of a drypolyphosphate-built alkyl aryl sulfonate powdered detergent has thefollowing composition:

Dodeoyl mercaptan condensed with eight to seventeen moles of ethyleneoxide.

The above liquid detergent solution remains clear at temperatures as lowas 45 F. When diluted with Water to a 0.07% washing concentration, thecomposition sudses well and is capable of Washing a greater number ofdishes than formulations containing equivalent quantities of eitherdetergent alone.

Example 2 Sixteen ounces of the following formulation is equivalent tonineteen or twenty ounces of a. polyphosphatebuilt alkyl aryl sulfonatepowdered detergent'for light duty use:

, Percent Nonic 218 1 a 24.4 Sodium phenyl polypropylene sulfonate:

Active 41.3

Inert 0.3

Ethyl alcohol 20.0

Water, perfume, et 14.0

LDodeoyl mercaptan condensed with eight to seventeen moles of ethyleneoxide.

The above liquid detergent solution remains clear at temperatures as lowas 45 F. When diluted with water to a 0.07% Washing concentration, thesolution sndses well and washes a greater number of dishes thanformulations containing equivalent quantities of either detergent alone.

Example 3 Awell balanced formulation of which sixteen ounces isequivalent for light duty use to nineteen or twenty ounces of a drypolyphosphate-built alkyl aryl sulfonate powdered detergent has thefollowing composition:

Percent Sodium phenyl polypropylene sulfonate (salt-free) 40.9 TritonX-l deodorized 1 27.1 Ethyl alcohol 16.5 Water, perfume, etc 15.5

To illustrate the enhanced effect due to the mixture of 8 ene sulfonateabove about the liquid detergent is not clear, containing a precipitateof active detergent. However, dishwashing data was obtained using suchdetergents as well, to complete the data:

Liquid detergent composition 1 (percent by weight) Example No.

Sodium phenyl Nonyl phenol polypropylene condensed with sulfonate 8 to17 moles (salt-free) ethylene oxide 63% total active detergent in eachcase, the remainder 21% ethyl alcohol, 16% water,

DISHWASHING TEST [Number of plates Washed in six quarts of water at 116F.]

.111. water Example No. p p

A comparison of this data showslExamples 4 to 8 and 13 to 15 to displaythe enhanced eflect due to the combination of these detergents.

Examples 16 to 23 At a 58% total active concentration, the followingdata is obtained:

phenyl polypropylene sulfonate and alkyl phenol ether 40 nonionicdetergent the following is presented:

Liquid detergegt complositlon l ercen Wei t Liquid detergent composition1 p y g (percent by Weight) Example No. Y Sodium phenyl Nonyl phenolExample I\o. 45 polypropylene condensed with Sodium phenyl Nonyl phenolsulfonate 8 to 17 moles polypropylene condensed with (salt-free)ethylene oxide sulfonate 8 to 17 moles (salt-free) ethylene oxide 63%total active detergent in each case, the remainder 21% ethyl alcohol,16% water.

DISH WASH ING 'rns'r [Number of plates Washed in six quarts of water at116 F.]

At the above concentrations of sodium phenyl polypropylene sulfonate theliquid detergent remains clear at temperatures down to 45 F. withoutseparation of solidv materials. At concentrations of phenyl polypropyl-58% total active detergent in each case, the remainder 26% ethylalcohol, 16% water.

DISHWASHING TEST [Number of plates washed in six quarts of Water at 116F.]

The above solutions remained clear and uniform with-' out separation ofsolid materials at temperatures down to 45 F. The enhanced effect due tothe combination of these detergents is evident in Examples 17 to 21.

9 Examples 24 to 27 [Percent by weight] Each of the above formulationsremained clear and uniform without separation of solid materials attemperatures as low as 45 F.

The following table summarizes the dishwashing capacities of theseformulations:

Example No. DISHWASHING TEST Ingredients [Number of plates washed in sixquarts of water at 116 F.] 24 25 26 27 50 p.p.m. water 180 p.p.m. waterSodium phenyl olypropylene sul- Example No.

fonate (salt-free? 43. 5 Alkyl polyethylene oxide tliioetlicr 25 25 4 34 g. 8 E- Polyethylene glycol (in w 300) Al hol 18.8 21.8 18. 8

66. 2 15. 7 12. 7 35 48 38 56 35 55 41 59 37 54 1 32 46 1 The phenylpropylene sulfonate in Examples 24, 25 and 27 was O1()- 35 56 33 43nite; in Example 26 it was Ultrawet K. 36. 50 34 59 Dodecyl mercaptancondensed with from eight to seventeen moles of ethylene oxide. I

The above solutions remained clear and uniform with- Examples 33 to 37out separation of solid materials at temperatures down Additio l f l i fh i ti are as f ll to 45 F.

The dishwashing capacity of these formulations is as [Percent by welghtlfollows: i

e Example No. Ingredients 50 .m. water 300 .m. water p p p p 33 34 35 3637 g g g g Ultrawet K 43. 5 43. 5 43. 5 43. 5 43. 5

Antarox A-40O L 25 Example 24- 16 29 15 26 Nonionio 218 3 25 Example 25s 14 e 13 NPG10 25 i 32 5o 57 Sterox SE 1 25 Triton X-100 25 Ethylalcohol 18. 75 18. 75 18. 75 18. 75 18. 75 s 7 14 13 Water 12. 75 12. 7512. 75 12. 75 12. 75 8 14 6 13 Example 26- 12 22 14 21 Example 27, 32 5035 57 35 1 Sodium phenyl polypropylene sulfouate (salt-free). In as in p2 Condensation product of alkyl phenol (alkyl of eight to sixteen carbonExamples 25 and 26 are used toatoms) with eight to twenty moles ofethylene oxide. gether 12 14 15 23 3 Dodecyl mcrcaptan condensed withfrom eight to seventeen moles 01' Increase in plates when poly ethyleneOXIdG oxide detergent is used (Example 4 Condensation product of oetylphenol and polyethylene glycol (eight 1 27) instead of polyethyleneglycol to twelve moles of ethylene oxide).

(Example 26) 20 28 21 36 The above solutions remained clear and uniformwith- Examples 24, 25 and 26 are not very satisfactory from the sudsingstandpoint, as is evident from the number of soiled plates which can bewashed. Example 26 is in fact, a little worse than Example 24, showingthat the polyethylene glycol has a depressing eflect upon suds.

It is clear that the use of phenyl polypropylene sulfonate and thioetherdetergents together has an enhanced effect upon sudsing, for the numberof plates washed with Example 27 is noticeably in excess of that of anyof the other examples.

A comparison of Examples 26 and 27 shows the polyethylene oxidethioether detergent significantly different from polyethylene glycol.

Examples 28 to 32 Additional formulations of the invention are asfollows:

[Percent by weight] Example N0. Ingredients Sodium Ororiite 43.5 43.543.5 43.5 43.5 Antarox A-40O Z 25 1 Sodium phenyl polypropylenesulfoiiate (salt-free).

2 Condensation product of alkyl phenol (allryl of eight to sixteencarbon atoms) with eight to twenty moles of ethylene oxide.

3 Dodecyl mercaptan condensed with from eight to seventeen moles ofethylene oxide.

4 Condensation product of octyl phenol and polyethylene glycol (eight totwelve moles of ethylene oxide).

out separation of solid materials at temperatures as low as 45' F.

. These dishwashing test results are typical:

1 Included for comparison.

All of the above compositions are satisfactory detergents fordishwashing purposes. The average are from 1 /2 to 2 times that of theExamples 24 and 25.

Examples 38 to 44 A series of compositions were formulated using SodiumNeolene 400 Sulfonate (sodium phenyl polypropylene sulfonate) and TritonX- (octyl phenol condensed with from eight to twelve moles of ethyleneoxide). The amounts of each detergentwere as set forth in the tablewhich follows. These were dissolved in a mixture of 26% ethyl alcoholand 16% water.

58% total active detergent in each case, the remainder 26% ethylalcohol, 16% water.

The compositions tested were tested for uniformity at low temperaturesby placing them in a freezing cabinet at --20 C. (4 F.) for seventyhours. This is a very extreme temperature but it will be noted from thefollowing table that all but two of the compositions remained a clearliquid at this temperature. The two compositions which solidified at '20C. (4 F.) remained liquid at temperatures as low as 45 F.

gen and alkali metal cations, R and R are alkyl groups of the typeformula C H and the entire alkyl chain has from twelve to fifteen carbonatoms and at least one R is a polypropylene group, and a nonionicdetergent polyethylene oxide ether of a hydrophobic organic compound,said nonionic detergent having the formula:

where R is a hydrocarbon group having from eight to eighteen carbonatoms, A is selected from the group consisting of oxygen and sulfur andx is a number from eight to twenty, representing the average number ofethylene oxide units in the polyethylene oxide chain, in the proportionof from one to twenty parts of the former to from three to one parts ofthe latter, dissolved in a solvent mixture of water and from 5 to of awater-miscible lower aliphatic alcohol.

2. A concentrated light duty liquid detergent in accordance with claim 1in which the nonionic detergent is an alkyl phenol ether of apolyethylene glycol.

3. A concentrated light duty liquid detergent in accord- PHYSICALCHARACTERISTICS OF COMPOSITIONS EXPOSED TO 20 TEMPERATURE FOR SEVENTYHOURS Physical state of liquid detergent formulations-Time of inspectionin hours Example 7 Solid Solid Solid Solid Solid Solid Solid. do do dodo do -do Do.

Clear liquid Clear liquid Clear liquid Clear liquid Clear liquid...Clear liquid- Clear liquid.

rlo' do do .do do do Do, do do do do Do. do do do "do Do. .(lo do do doDo.

where M is selected from the group consisting of hydroance with claim 1in which the nonionic detergent is an ether of a polyethylene glycol andan alcohol of high molecular weight.

4. A concentrated light duty liquid detergent in accordance with claim 1in which the nonionic detergent is an alkyl thiophenol ether of apolyethylene glycol.

5. A concentrated light duty liquid detergent in accordance with claim 1in which the nonionic detergent is an ether of a polyethylene glycol anda mercaptan of high molecular weight. 7

6. A concentrated light duty liquid detergent in accordance with claim 1in which the alcohol solvent is ethyl alcohol.

7. A concentrated light duty liquid detergent in accordance with claim 1in which the alcohol solvent is isopropyl alcohol.

References Cited in the file of this patent UNITED STATES PATENTS1,970,578 Schoeller Aug. 21, 1934 2,213,477 Steindorfi Sept. 3, 19402,469,493 Barker May 10, 1949 2,477,383 Lewis July 26, 1949 2,607,740Vitale Aug. 19, 1952 2,642,400 Harris June 16, 1953

1. A CONCCENTRATED LIGHT DUTY LIQUID DETERGENT WHICH REMAINS CLEAR ANDUNIFORM WITHOUT SEPARATION OF SOLID MATERIALS AT TEMPERATURE AS LOW AS45*F. COMPRISING AT LEAST 50% ACTIVE DETERGENT CONSISTING ESSENTIALLY OFA SUBSTANTIALLY SALT-FREE DETERGENT PHENYL POLPROPYLENE SULFONATE HAVINGTHE GENERAL STRUCTURE: